SAT Section 2: Mathematics: SAT2-MATHEMATICS

Correct Answer: D

The order of the four songs is important. The orderings A, B, C, D and A, C, B, D contain the same four songs, but in different orders. Both orderings must be counted. The number of six-choose-four orderings is equal to (6)(5)(4)(3)= 360.

Correct Answer: B

Explanation:

Angle CBD and angle PBZ are alternating angles — their measures are equal. Angle PBZ= 70 degrees. Angle PBZ+ angle ZBK form angle PBK. Line PQ is perpendicular to line JK; therefore, angle PBK is a right angle (90 degrees). Angle ZBK= angle PBK– angle PBZ= 90 – 70 = 20 degrees.

Correct Answer: B

Explanation: Since triangle DEC is a right triangle, triangle AED is also a right triangle, with a right angle at AED. There are 180 degrees in a triangle, so the measure of angle ADE is 180 – (60 + 90) = 30 degrees. Angle A and angle EDC are congruent, so angle EDC is also 60 degrees. Since there are 180 degrees in a line, angle BDC must be 90 degrees, making triangle BDC a right triangle. Triangle ABC is a right triangle with angle A measuring 60 degrees, which means that angle B must be 30 degrees, and BDC must be a 30-60- 90 right triangle. The leg opposite the 30-degree angle in a 30-60-90 right triangle is half the length of the

hypotenuse. Therefore, the length of DC is 15/2 units.